232 THE VITAMINES 



vitamine C was more stable because of the acid present. This 

 idea was confirmed by the fact that other acid juices, like raspberry 

 and sour dock juice, show the same stability towards heating. The 

 heat stability of cabbage and dandelion juice was markedly increased 

 on the addition of acid, but permanent stability could not be obtained. 



The last finding was made use of in extractions. If freshly dried 

 cabbage is extracted with alcohol to which a little citric acid is added, 

 instead of with pure alcohol, the extracts thus obtained are much 

 more active on guinea pigs. Other isolation experiments, such as 

 dialysis or extraction with petroleum ether, were valueless. Hoist 

 and Frolich were unable to favorably influence scurvy in guinea pigs 

 by intraperitoneal injections. 



In a later communication, Hoist and Frolich (620) stated that 

 cabbage dried at 37C. and stored in a desiccator still contained 

 vitamine C after 13 months. It was possible also to obtain an 

 active substance by extracting cabbage with a mixture of alcohol 

 and glycerine. This was also the case with extractions made with 

 dilute alcohol, to which 0.5 per cent citric acid had been added. Hot 

 80 per cent alcohol with 0.5 per cent citric acid likewise extracts 

 vitamine C from freshly dried cabbage. Since the experiments of 

 Hoist and Frolich in 1913, no real progress has been made, in spite 

 of the numerous publications that have appeared. 



Shortly thereafter, the author undertook a chemical fractionation 

 of vitamine C, using the same methods as in the yeast fractionation, 

 but the results obtained were not very satisfactory. The investiga- 

 tion failed chiefly because of the lack of knowledge of scurvy in 

 guinea pigs, as well as of the behavior of vitamine C which at that 

 time had hardly been recognized. Although more firmly established 

 data are available on this subject at present, the chemistry of this 

 vitamine has thus far not progressed. In 1912 we investigated, in 

 this respect, milk, potatoes and lime juice, using guinea pigs and 

 rabbits kept on water and oats. The guinea pigs died in about 20 

 to 30 days with marked scorbutic symptoms. After the addition of 

 fresh potato juice, the animals died after 36 days, while after the 

 purification of this juice with lead acetate, the animals died after 27 

 days. A daily addition of 25 cc. milk had a definite inhibitory effect 

 on the scorbutic symptoms, while on addition of 50 cc. milk, the 

 symptoms of scurvy were absent even after 50 days, the animals 

 sometimes gaining weight; we shall discuss the dissimilar results of 



